1. Technical Field
The disclosure relates to a three-dimensional (3D) display. More particularly, the invention relates to a switchable 3D display.
2. Description of Related Art
In recent years, as display technology advances, users have become more and more demanding on display quality of displays, e.g., image resolution, color saturation, and so forth. However, other than the requirements for high resolution and high color saturation, in order to satisfy the need of the users to view realistic images, displays which are capable of displaying 3D images have been developed. Additionally, displays with the touch-sensing functions have gain popularity among users.
In the current 3D image display technologies, a parallax barrier controlling images captured in respective eyes of a viewer is configured between a display panel and the viewer. According to visual characteristics of human eyes, a 3D image is produced when two images with the same content but different parallax are respectively captured by a viewer's left and right eyes. Said parallax barrier often has a plurality of slits that allow the viewer to see different images respectively from his or her left eye and right eye. Since the conventional parallax barrier prevents the 3D display from displaying normal two-dimensional (2D) images, a switchable parallax barrier has been proposed to display both the 2D and the 3D images on the display.
FIG. 1A is a schematic top view illustrating a first electrode structure of the conventional switchable parallel barrier. FIG. 1B is a schematic cross-sectional view taken along a line I-I depicted in FIG. 1A. With reference to FIG. 1A and FIG. 1B, the conventional switchable parallax barrier 10 includes a plurality of odd electrodes 12 electrically connected to one another, a plurality of even electrodes 14 electrically connected to one another, a scan electrode 16, and a liquid crystal layer 18. The odd electrodes 12 and the even electrodes 14 are coplanar and electrically insulated from one another. The scan electrode 16 is opposite to the odd electrodes 12 and the even electrodes 14. The liquid crystal layer 18 is located between the scan electrode 16 and the odd and even electrodes 12 and 14. The odd electrodes 12 and the even electrodes 14 are alternately arranged. The odd electrodes 12 electrically connected to one another constitute one finger-shaped pattern, and the even electrodes 14 electrically connected to one another constitute another finger-shaped pattern.
Since the odd electrodes 12 and the even electrodes 14 are coplanar, a gap G between each of the odd electrodes 12 and each of the even electrodes 14 is required, such that the odd electrodes 12 and the even electrodes 14 can be independently operated. As indicated in FIG. 1B, the barrier ratio of the switchable parallax barrier is calculated and represented by the equation: W1/(G+W2+G+W1)=W2/(G+W1+G+W2). Here, W1 denotes the width of each of the odd electrodes 12, W2 denotes the width of each of the even electrodes 14, and W1 is approximately equal to W2. Besides, G denotes the gap between each of the odd electrodes 12 and each of the even electrodes 14, and G is not equal to zero. Generally, given that the width of each of the odd electrodes 12 is equal to the width of each of the even electrodes 14 (i.e., W1=W2), and that the barrier ratio of the switchable parallax barrier 10 is approximately equal to 50%, the display having the switchable parallax barrier can achieve the most favorable display effects. However, it can be learned from the above-mentioned equation that the barrier ratio of the conventional switchable parallax barrier 10 is undoubtedly less than 50%. Therefore, the conventional switchable parallax barrier 10 is not very much likely to accomplish the expected 3D display effects.